Degenerative disc disease is a common age related low back problem. It can be a significant cause of low back pain. The best treatment for it is non-operative. Back strengthening to stabilize the spine and application of topical pain measures should be tried first.

Knee crepitus can be from multiple causes. Painless crepitus can be ignored. So, I won't advice for crepitus knee treatment as such.. Crepitus from knee cap problems can be cured with hip and knee strengthening. Crepitus from cartilage irregularities or loose pieces often need minor keyhole surgery. Painful crepitus from arthritis is initially treated with physical therapy and surgery when therapy stops helping. 

Degenerative disc disease is a common age related low back problem. It can be a significant cause of low back pain. The best treatment for it is non-operative. Back strengthening to stabilize the spine and application of topical pain measures should be tried first.

Prevention of worsening of degenerative disc disease is by decreasing the stress on the degenerated discs. Weight loss and avoidance of weight lifting and high impact activities decrease the stress and pain.